Visible Air-Spaced Achromatic Doublets, AR Coated: 350 - 700 nm
- Minimal Focal Shift Over the Design Wavelength Range
- Superior Performance When Compared to Cemented Doublets
- 1" Outer Diameter Aluminum Housing
Each mount includes an engraved arrow
indicating the direction of light propagation
required to collimate a point source.
|Coating Rangea||350 - 700 nm|
|Design Wavelengths||486.1, 587.6, 656.3 nm|
|Surface Quality||20-10 Scratch-Dig
(to Prevent Scattering from
|Clear Aperture||Ø20 mm|
|Irregularity per Surface||<λ/4 at 633 nm|
|Focal Length Tolerance||±1% at 587.6 nm|
|Reflectance||Ravg < 0.5% (350-700 nm)|
|Housing||Ø1" 6061-T6 Aluminum Barrel|
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Air-Spaced Achromatic Doublet in an SM1L30C Slotted Lens Tube with Two SM1RR Retaining Rings
- Air-Spaced Doublet Design Provides Superior Aberration Performance than Singlet Lenses
- Ø20 mm Clear Aperture
- 1" Outer Diameter for Mounting Inside a Ø1" Lens Tube
- AR Coating for the 350 - 700 nm Range
Thorlabs' Air-Spaced Achromatic Doublets are designed to provide superior spherical and chromatic aberration correction. Air-Spaced Doublets have two more degrees of freedom than cemented doublets because the interior lens surfaces do not need to have the same curvature. These extra variables allow the performance of these air-spaced doublets to exceed the performance of equivalent cemented doublets in some cases. For details, please see the Lens Comparison tab. The air-spaced design is also highly resistant to laser damage, since no cement is utilized in the fabrication process. Although these lenses have an AR coating for the 350 - 700 nm range deposited on both surfaces, the glass they are fabricated from displays limited or no transmission in the UV (<400 nm). Hence, please refer to the table below for exact specifications and transmission plots for each air-spaced doublet.
The doublets are pre-mounted in an aluminum barrel with tight tolerances on lens and barrel diameter to minimize the effects of lens decentering. Each mount includes an engraving with the part number, AR coating wavelength, focal length, and the direction of light propagation required to collimate a point source. The mount has a 1" outer diameter for mounting inside a Ø1" lens tube (as shown in the photo to the right).
Note: We do not recommend disassembly of these lenses, as this may affect performance.
The table below contains links to pop-ups with plots containing a comparison of the theoretical performance of an air-spaced achromatic doublet and a cemented achromatic doublet with the same focal length. Comparisons are made for the transmitted wavefront error and spot radius. Raw data from each graph below can be downloaded by clicking here.